Lecture 8 (Logic)

What does the rule of Existential Specification let us do?

1. A.Conclude ∃x R(x) once R holds of one named individual
2. B.Replace ∃x R(x) with ∀x R(x) when the domain is non-empty
3. C.Introduce R(α) for a fresh ambiguous name α from ∃x R(x)
4. D.Drop the quantifier from ∀x R(x) and plug in any term